Aliexpress
Click here… to search for Realme X2 8/128GB CN Blue on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (305.99 USD): BGCITYADS2019
Coupon (316.19 USD): od7off
(CouponsFromChina.com tip: just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGRMX28
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Realme X2 8/128GB CN Blue is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).